Brand catalog
EXTAR PROTON
Custom handmade steel frames for road, touring, mini-velo, and tandem bikes.
EXTAR PROTON is an Osaka handmade-steel bicycle-frame brand offering custom road, touring, mini-velo, and tandem frames.
Company history
Hashiguchi Seisakusho builds EXTAR PROTON handmade steel frames in Osaka. The official page describes custom orders spanning traditional road and touring bikes, modern disc-brake frames, mini-velos, and tandems. No founding year was found.
- Headquarters
- Higashinari, Osaka, Japan
- Country
- JP
EXTAR PROTON logo from the official brand website.
Verified public catalog
Recently updated EXTAR PROTON products
Exact variants are ordered by their latest catalog update, with a stable tie-breaker. Personal bicycle history remains separate.
No public products yet
No reviewed products with a public canonical route are available here yet.